The Big Challenge...

Fingerprinting the Salmon

In the River Tay salmon from different tributaries constitute separate breeding populations.

This structuring of the population is very important as it helps to main differences between salmon, for example the highly varied timing of runs of fish returning to different tributaries throughout the year.

Recent advances in genetic techniques have meant that for some rivers at least, it has proved possible to “fingerprint” juvenile salmon from individual tributaries and then to use this information to be able to identify the tributaries of origin of fresh run adult fish as they enter the river.

This type of information is important because it aids the identification of vulnerable salmon populations and can help target conservation measures on those fisheries which impact on those sub-populations which need most help.

As part of a pan-Scotland initiative the Tay Foundation, assisted by TDSFB, have provided samples of juvenile salmon to the RAFTS FASMOP project in order to create a genetic baseline for the tributaries of the Tay.

However, to date, the genetic markers used have not quite provided the degree of resolution found in some other rivers, so other types of markers are being trialled as part of this project.

It is hoped that the genetic markers already used will discriminate sufficiently to allow Tay fish, or at least Scottish fish, to be differentiated from other countries fish caught by experimental trawling in the north Atlantic. This is a major part of the SALSEA project which is due to report later this year. This large international research effort is perhaps the biggest project ever mounted to help understand the problems currently being faced by salmon while at sea.

Funding for the fingerprinting work was provided by the Scottish Government and the Atlantic Salmon Trust and organised by RAFTS. The completed report on the project can be accessed here.

If the genetic fingerprint of different stocks of salmon within the Tay can be identified it will open up all sorts of possibilities for improving the management of salmon in future.